package com.yzy.yuzhouwaimai.controller;

import com.yzy.yuzhouwaimai.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${yuzhou.path}")
    private String basePath;
    /**
     * 文件上传
     * 传入参数的值一定要和前端保持一致
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        log.info(file.toString());
        //获取原始文件名
        String originalFilename = file.getOriginalFilename();
        //获取原文件后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));


        //使用UUID重新生成文件名，防止文件名重复，发生覆盖
        String fileName = UUID.randomUUID().toString()+suffix;

        //创建一个目录对象
        File dir = new File(basePath);
        //判断当前目录是否存在
        if (!dir.exists()) {
            //目录不存在需要创建
            dir.mkdirs();
        }

        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        //输入流，读取文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath)+name);

            //输出流，将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();
            //设置传输类型
            response.setContentType("image/jpeg");


            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();

        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}
